lib/MooseX/ClassAttribute/Trait/Application/ToRole.pm

   1 package MooseX::ClassAttribute::Trait::Application::ToRole;
   2
   3 use strict;
   4 use warnings;
   5
   6 use Moose::Util::MetaRole;
   7 use MooseX::ClassAttribute::Trait::Application::ToClass;
   8 use MooseX::ClassAttribute::Trait::Application::ToInstance;
   9
  10 use namespace::autoclean;
  11 use Moose::Role;
  12
  13 with 'MooseX::ClassAttribute::Trait::Application';
  14
  15 sub apply_class_attributes {
  16     my $self  = shift;
  17     my $role1 = shift;
  18     my $role2 = shift;
  19
  20     $role2 = Moose::Util::MetaRole::apply_metaclass_roles(
  21         for            => $role2,
  22         role_metaroles => {
  23             role => ['MooseX::ClassAttribute::Trait::Role'],
  24             application_to_class =>
  25                 ['MooseX::ClassAttribute::Trait::Application::ToClass'],
  26             application_to_role =>
  27                 ['MooseX::ClassAttribute::Trait::Application::ToRole'],
  28             application_to_instance => [
  29                 'MooseX::ClassAttribute::Trait::Application::ToInstance'
  30             ],
  31         },
  32     );
  33
  34     foreach my $attribute_name ( $role1->get_class_attribute_list() ) {
  35         if (   $role2->has_class_attribute($attribute_name)
  36             && $role2->get_class_attribute($attribute_name)
  37             != $role1->get_class_attribute($attribute_name) ) {
  38
  39             require Moose;
  40             Moose->throw_error( "Role '"
  41                     . $role1->name()
  42                     . "' has encountered a class attribute conflict "
  43                     . "during composition. This is fatal error and cannot be disambiguated."
  44             );
  45         }
  46         else {
  47             $role2->add_class_attribute(
  48                 $role1->get_class_attribute($attribute_name)->clone() );
  49         }
  50     }
  51 }
  52
  53 1;
  54
  55 __END__
  56
  57 =pod
  58
  59 =head1 NAME
  60
  61 MooseX::ClassAttribute::Trait::Application::ToRole - A trait that supports applying class attributes to roles
  62
  63 =head1 DESCRIPTION
  64
  65 This trait is used to allow the application of roles containing class
  66 attributes to roles.
  67
  68 =head1 AUTHOR
  69
  70 Dave Rolsky, C<< <autarch@urth.org> >>
  71
  72 =head1 BUGS
  73
  74 See L<MooseX::ClassAttribute> for details.
  75
  76 =head1 COPYRIGHT & LICENSE
  77
  78 Copyright 2007-2008 Dave Rolsky, All Rights Reserved.
  79
  80 This program is free software; you can redistribute it and/or modify
  81 it under the same terms as Perl itself.
  82
  83 =cut